Brandon Day and Gina Allen were rescued Tuesday after searchers spotted smoke from a fire the Dallas couple had started.
As Day thanked their rescuers later Tuesday, he said he and Allen were also grateful to the backpack's owner, John Donovan, a retired Virginia social worker who disappeared during a hike in May 2005.
"I want to thank him for helping save our lives," Day said.
Papers in the orange backpack connected it to Donovan, and searchers planned to scour the area this week for the missing man's remains, Riverside County sheriff's Sgt. Earl Quinata said.
"Even in his death, he was helping people," Donovan's longtime friend, Chris Hook, said from Richmond, Virginia.
Donovan, an experienced hiker, was last seen in the San Jacinto Wilderness on May 3, 2005, about two weeks after he retired from Central State Hospital in Petersburg, Va. The 60-year-old planned to hike the 2,650-mile Pacific Crest National Scenic Trail, from Southern California to the Canadian border.
A longtime friend of Donovan, Chris Hook, told the Dallas Morning News Tuesday that he hoped the discovery would soon lead to the recovery of the retired social worker's remains.
"That is amazing," Hook, told the Morning News from his home in Richmond, Va. "In a way, John might have saved their lives. His pack being there helped them to be found. That's how John's life went. Even in his death, he was helping people."
Hook said he assumed his friend got hurt and froze to death in a snowstorm that blew on the last night he was seen alive.
Day, 28, and Allen, 24, were in Southern California for a financial convention.
They got lost west of Palm Springs when they wandered off a trail near the Palm Springs Aerial Tramway during what was supposed to be a day hike.
They said they spent Saturday night in a cave, dressed only in light clothing and without any supplies, then followed a creek Sunday and Monday that they hoped would lead them down the mountain to safety. The creek led to a gorge, where they found Donovan's campsite.
When both Day and Allen missed their flights home and relatives and friends became concerned after they couldn't reach them by phone, friends and family alerted the authorities, the Morning News reports.
Riverside Mountain Rescue crews began searching about Monday afternoon.
Searchers in a sheriff's helicopter spotted them Tuesday about 2 1/2 miles from the tramway. The two were treated at a hospital for dehydration, bumps and bruises.